GU demands a price increase on the entire house

With the argumentation of the general contractor, he could also delay the installation of the doorbell by 10 years and then demand the house price from you in 10 years. (Yes, this is exaggerated, but that’s what it comes down to)

You have described the methodology (of billing for development and road construction contributions) very clearly here ;-)

Similar to how you pay instalments for your gas consumption throughout the year, but what counts in the end is the annual statement.

However, with gas consumption, it is easy to take an intermediate meter reading in case of price increases, because the meter measures the actual consumption ...

But I also refuse to pay more for the entire house. Only for the trades or the items in the payment plan that are still open.

... while the payment plan is only designed to offset the instalments against the contractor’s liquidity consumption due to expenditures for preliminary services, but is not suitable to compensate for a fictitious "partial completion." In this respect, the comparison “system-related” falls short.

I have already signed 2 general contractor contracts and in neither contract was a term for price fixation provided. I consider that unprofessional, especially the explicitly short period of 12 months in your contract.

A price fixation “off limits” would be sheer madness – at best, only very large providers survive that, and even they not always. The duration is alright, only at the start of the period the “consumer” tends to forget the difference between braking distance and stopping distance.

I find it surprising. How does he want to keep the prices then? Especially in today's times…

Initial meeting: January 2021 Contract signing: August 2021 Start of construction: January 2022 Price increase during this period due to force majeure (Corona waves, shortage of raw materials, war and its impact): 0 euros Our biggest annoyance so far was that the plasterers messed up a window key. :)

I want an agreement that is reasonable for both sides. But only in areas that we want and can afford to pay for. I am looking forward to tomorrow. I will report back :)

A price commitment being "off limits" would be sheer madness – at best, only very large providers would survive, and not always them either. The duration is already fine; only at the start of the deadline, the "consumer" tends to forget the difference between braking distance and stopping distance.

That would have to be the start of construction, right? Otherwise, it would be confusing. A building permit can take months. Many construction companies have 12 months as construction time in the contract, some even minus the winter months, so rather 15. It is foreseeable that 12 months will be exceeded. And even if the deadline started at the beginning of construction, I still find it extremely one-sided as a contractual clause. Ultimately, only the construction company has control over the time needed until completion. With that, they could simply dawdle 1-2 weeks between each trade and then slap a big chunk on the former "flat rate" in month 14?

But don’t be surprised if nothing (in words: zero) progresses at the house in the coming months.
This does not count towards the construction time guarantee, as the client has not paid an issued invoice.

Maybe there are some people like you, then I’m not surprised that the construction companies get around like that!
There is surely a construction schedule. When is the contractor supposed to be finished? Which services are still missing?
Withholdings already made?
Be prepared for everything, but of course seek the conversation first.

Initial meeting: January 2021
Contract signing: August 2021
Start of construction: January 2022

Price increase during this period due to force majeure (Corona waves, raw material shortages, war and its impact): 0 euros

Our biggest annoyance so far was that the plasterers messed up a window key. :)

Well, that's no wonder, because by far the biggest price increase happened in 2021, and you were already involved then.
We signed in November 2020, the price lock was valid until November 2021, and the increase was 15%.
The people around us who signed with the same general contractor in June/July/August 2021, as "new customers," paid an even higher surcharge, whereas they were lenient with us and deducted 5%...